Two-dimensional pattern formation in surfactant-mediated epitaxial growth

TL;DR

This paper presents a theoretical model showing how surfactants influence two-dimensional pattern formation in epitaxial growth, revealing a transition from fractal to compact islands influenced by temperature and flux, aligning with experimental observations.

Contribution

It introduces a simple theoretical model explaining surfactant effects on island morphology transitions during epitaxial growth.

Findings

Fractal-to-compact island transition can be induced by temperature or flux changes.

The model's predictions align qualitatively with recent experimental results.

Surfactants significantly alter the energy barriers affecting island shapes.

Abstract

The effects of a surfactant on two-dimensional pattern formation in epitaxial growth are explored theoretically using a simple model, in which an adatom becomes immobile only after overcoming a large energy barrier as it exchanges positions with a surfactant atom, and subsequent growth from such a seed is further shielded. Within this model, a fractal-to-compact island shape transition can be induced by either decreasing the growth temperature or increasing the deposition flux. This and other intriguing findings are in excellent qualitative agreement with recent experiments.